The study aimed to assess the prevalence and correlates of hazardous, harmful or dependent alcohol use (HHDA) and drug use among persons 15 years and older in South Africa. In a national cross-sectional 2017 survey, 39,210 persons 15 years and older (Median=34 years) responded to a questionnaire on substance and health variables. Logistic regression was used to assess the determinants of HHDA and any drug use. Results indicate that (10.3%) engaged HHDA, 16.5% among males and 4.6% among females, and past 3-month drug use was 8.6%, 13.3% among males and 4.1% among females. In adjusted logistic regression analysis, among men, middle age (25-34 year olds), higher education, urban residence, drug use, and psychological distress were positively and Indian or Asian and White population groups were negatively associated with HHDA. Among women, middle age (25-34 year olds), Coloureds, residing on rural farms and urban areas, drug use and psychological distress were positively and older age (55 years and older), and Indians or Asians were negatively associated with HHDA. In adjusted logistic regression analysis, among men, having Grade 8-11 education, Coloureds, being unemployed, and HHDA were positively and middle and older age (25 years and older) and being a student or learner were negatively associated with past 3-month any drug use. Among women, Coloureds, Indians or Asians, and HHDA were positively and older age (45 years and older) was negatively associated with past 3-month and drug use. About one in ten participants engaged HHDA and any drug use, and several sociodemographic and health indicators were identified associated with HHDA and any drug use.